python 3.x – Loop and time computation problem

I want to do a program, where he reads an activity and the time spent on it.

example:
Wash the door, 10:30, stop 01:30

I currently have 3 problems:

1º The way my code is currently can not put it to
because of the calculation of hours.

2º I put that it would be done 5 activities in case I would like to leave without limit pre-established.

3º I would also like to put a keyword so that it tells me the imprint, as for example if I type "end", this gives the imprint with all the collected information.

since datetime import datetime
activity = [] #List of services
departure_time = [] #List Time
end_time = [] #List End Time
account = 0
counting! = 5:
try:
activity_p = input (f) Enter the name of {count + 1} º Activity: & # 39;)
account + = 1
time_initial_p = input (& # 39; Enter the initial time: & # 39;)
time_final_p = input (Enter the end time: & # 39;)
activity.append (activity_p)
start_time.append (start_time)
final_time.append (final_time)
d = H,
except ValueError:
print (Enter a valid value, example 10: 30 & # 39;)

activity_1 = activity [0]
initial_time_1 = initial_time [0]
final_time_1 = final_time [0]
value_1 = (datetime.strftime (end_time_1, d) - datetime.strftime (start_time1, d)

activity_2 = activity [1]
start_time_2 = start_time [1]
final_time_2 = final_time [1]
value_2 = (datetime.strftime (end_time2, d) - datetime.strftime (start_time2, d)

activity_3 = activity [2]
start_time_3 = start_time [2]
final_time_3 = final_time [2]
value_3 = (datetime.strftime (end_time3, d) - datetime.strftime (start_time3, d)

activity_4 = activity [3]
start_time_4 = departure_time [3]
final_time_4 = final_time [3]
value_4 = (datetime.strftime (end_time4, d) - datetime.strftime (start_time4, d)

activity_5 = activity [4]
initial_time_5 = initial_time [4]
end_final_5 = end_time [4]
value_5 = (datetime.strftime (end_time5, d) - datetime.strftime (start_time5, d)

print (f {activity_1}, {start_time_1} as {end_time_1}, Time passed {value_1} & # 39;)
print (f {activity_2}, {start_time2} as {end_time_2}, past time {value_2} & # 39;)
print (f {activity_3}, {start_time3} as {end_time3}, Time passed {value_3} & # 39;)
print (f {activity_4}, {start_time4} as {end_time4}, Time passed {value_4} & # 39;)
print (f {activity_5}, {start_time_5} as {end_time_5}, past time {value_5} & # 39;)